Tianmen Mountain (Chinese: 天門山; pinyin: Tiānmén Shān), meaning Heaven's Gate Mountain, is a mountain located within Tianmen Mountain National Park, Zhangjiajie, in the northwestern part of Hunan Province, China.

A cablecar was constructed in 2005 by the French company Poma from nearby Zhangjiajie railway station to the top of the mountain. Tianmen Mountain Cableway is claimed in tourist publications as the "longest passenger cableway of high mountains in the world", with 98 cars and a total length of 7,455 m (24,459 ft) and ascent of 1,279 m (4,196 ft). The highest gradient is 37 degrees. Tourists can walk on kilometres of paths built along the cliff face at the top of the mountain, including sections with glass floors. An 11 km (7 mi) road with 99 bends also reaches the top of the mountain and takes visitors to Tianmen cave, a natural arch in the mountain of a height of 131.5 m (431.4 ft).

The Tianmenshan Temple is located on the summit, with chairlift or footpath access. The original temple here was built during the Tang dynasty, and destroyed during the first part of the 20th century. In 1949, as the Chinese Communist Revolution neared its end, construction of a new temple, with Tang dynasty architecture, commenced; the temple now sits on landscaped grounds covering 2 hectares (4.9 acres).

In 2007, Alain Robert scaled the cliff below the arch, bare-handed and without protection; a plaque commemorates his feat.

The World Wingsuit League held the first and second World Wingsuit Championships in Tianmen. On October 8, 2013, during a training jump for the second world championships, Viktor Kováts plunged to his death when he was unable to open his parachute.

In August 2016, a glass skywalk overlooking Tongtian Avenue, called the "Coiling Dragon Cliff", opened to the public.

In February 2018, a hybrid Range Rover SUV driven by Ho-Pin Tung climbed the 45-degree angle staircase of 999 steps to Heaven's Gate using a combination of gasoline and electric battery power.